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Solve x^2 - 2x - 15 = 0

This is a simple quadratic equation. To answer the question, it must first be factorised before it can be solved. To do this, two numbers need to be found which multiply to make the constant term and have a ...
JK
Answered by Jack K. Maths tutor
18440 Views

Make t the subject of this equation: x=4t-7

x=4t-7 take the -7 over first, swapping the sign as it passes over the equals sign x+7=4t 4t = 4*t so we need to divide the other side of the equation by 4 1/4(x+7)=t
LC
Answered by Louise C. Maths tutor
3718 Views

Find the value of x in the equation x^2 - 2x + 1 = 0

Factorise: X^2 means 2 brackets (x )(x )=0 factors of 1 = 1 (x 1)(x 1)=0 to get minus 2 you must do (-1) + (-1) so (x-1)(x-1)=0 therefore x-1=0 and x=1
LC
Answered by Louise C. Maths tutor
4180 Views

Can lymphocytes have proteins that are complementary to host cell antigens?

You only kill off the ones that are reactive to host antigens (read: the ones that would attack your own cells!). So normal lymphocytic function isn't affected. Because of the nature of the immune system (yo...
SM
Answered by Scott M. Biology tutor
3725 Views

Why is there no wave for atrial repolarisation in the electrocardiogram?

While atrial repolarisation exists, you actually can't see it in the ECG! I can draw you a diagram of a normal cardiac cycle: this is the P wave, that you'll know represents the DEpolarisation of the atria. ...
SM
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